This invention relates generally to apparatus for making flexible packages, and more particularly to apparatus for applying twist-ties to reclosable, flexible packages.
Various types of flexible packages for holding particulate materials, e.g., ground or whole bean coffee, cereals, cookies, etc., have been disclosed in the patent literature and are commercially available today. xe2x80x9cTwist-tiesxe2x80x9d (sometimes also referred to as xe2x80x9ctin-tiesxe2x80x9d) are frequently incorporated into such packages to enable the packages to be reclosed for multiple serving usage. In particular, such twist-ties are elongated strips commonly made of either plastic and wire or paper and wire, with the wire being embedded in the plastic or paper. The twist-tie is fixedly secured on one of the panels of the package adjacent the package""s mouth. After the mouth of the package has been opened and some of the package""s contents removed, the package can be reclosed by folding or rolling the upper end (the mouth) of the package about the twist-tie, with the ends of the twist-tie extending beyond the margins of the rolled/folded portion. The ends of the twist-tie can then be bent or folded over the rolled/folded mouth to prevent it from unrolling/unfolding, thereby keeping the mouth closed to prevent air from reaching the remaining contents in the package.
Heretofore the application and securement of a twist-ties to poly-laminate or other material flexible packages on an assembly line has been accomplished in several ways. For example, in one way an applicator is used to apply, e.g., spray, hot glue to one face of a strip of twist-tie material while the strip is held in vertical plane on a wheel or disk arranged to be rotated about a horizontal axis. Once the glue has been applied to the twist-tie the disk is rotated 90 degrees to carry the twist-tie with its adhesive-bearing face directed toward a horizontally oriented flexible package (e.g., bag) onto which it is to be secured. The bag is then pressed against the glue-bearing twist-tie. This method of applying twist-tie to a flexible package is shown in U.S. Pat. No. 5,389,190 (Larsen et al.).
A second way of applying a twist-tie to flexible packages on an assembly line is to apply, e.g., spray, the hot glue directly to a preselected area on each bag while the bag is held in a vertical plane. Then the twist-tie can be pressed onto the bag in the area bounded by the applied glue.
Both of such methods of application suffer from one or more drawbacks. For example, the disadvantage of applying glue to the twist-tie on a disk and then rotating the disk, as described above, is that the glue is applied from a horizontal direction onto a vertically oriented twist-tie strip. Accordingly, the force of gravity tends to pull the hot glue downward and away from (off) the twist-tie strip as the strip is carried into a horizontal orientation for application to a horizontally oriented bag. If there are inconsistencies in the glue material, the application of the glue to the twist-tie becomes unreliable, resulting in misapplication of the twist-tie to the package.
The disadvantages of applying glue directly to the bag while the bag is held in a vertical orientation and then pressing the twist-tie against the glue-bearing area on the bag is three-fold. First, since the glue is applied from a horizontal direction onto a vertically oriented bag, the force of gravity will also act to pull the glue downward and away from (off) the area of the bag to receive the twist-tie strip. If there are inconsistencies in the glue material, the application of the glue to the twist-tie bearing portion of the bag becomes unreliable, resulting in misapplication of the twist-tie to the bag, as well as xe2x80x9cstringingxe2x80x9d of residual glue between the glue applicator head and the bag, thereby resulting in an off-quality bag (i.e., a bag with glue extending out beyond the margins of the twist-tie). The second disadvantage of this method of twist-tie application is that since the bag is formed of a flexible material, e.g., a polylaminate, if the bag flexes between the glue application and the twist-tie application, the twist-tie may not be placed onto the glue strip. The third disadvantage is that if the bag is missing on the conveyor or other device for carrying the bags to the glue head and the glue head is activated, then the hot glue can be dispensed into the machine, resulting in reliability and safety issues.
Examples of other apparatus for applying twist-ties to packages are found in the following U.S. Pat. Nos. 3,534,520 (Moran), 3,825,039 (Crabb), 3,890,190 (Eburn, Jr. et al.), 3,895,989 (Lucas), 3,919,8290 (Burford et al.), 4,420,355 (Saur), 4,490,960 (Klemestrud), 4,559,766 (Matsushita), 4,559,977 (Dilley), 4,586,412 (Johnson), 4,655,264 (Dilley), 4,660,351 (Saitoh), 4,696,244 (Sampson et al.), 4,730,434 (Knudsen), 5,045,042 (Rutledge), 5,121,682 (Parker et al.) and 5,402,619 (Nelson et al.).
These and other objects of the instant invention are achieved by providing apparatus and a method for applying twist-ties to a flexible packages. Each package comprises a front panel including an exterior surface. Each of the twist-ties comprises a strip of material having a first and a second opposed faces.
The apparatus basically comprises a glue applicator, a supply of twist-tie material, a carrier, and a package support. The package support is arranged to hold the package at a first station in an orientation, whereupon the front panel of the package is oriented in a vertical plane. The carrier has a twist-tie receiving face and is arranged to be oriented in a first position, wherein its twist-tie receiving face is in a horizontal plane. The supply of twist-tie material is arranged to sequentially provide respective twist-ties to the twist-tie receiving face of the carrier so that the first face of each respective twist-tie is facing upward. The glue applicator is disposed above the carrier and arranged for applying glue downward onto the upwardly facing first face of each respective twist-tie.
The carrier is pivotable to a second position after the glue is applied to the first face of the twist-tie, wherein the first face of the twist-tie is oriented in a vertical plane facing the exterior surface of the front panel of the package on the package support at the first station. The carrier is also movable in a horizontal direction to carry the twist-tie with the glue on its first face into engagement with the exterior surface of the front panel of the package to fixedly secure the twist-tie thereon.